The Effects of Blood Flow Restriction Training on

The Effects of Blood Flow Restriction Training on VO 2 max and 1. 5 Mile Run Performance William Ursprung and John Smith, Ph. D. Texas A&M University-San Antonio Abstract Blood flow restriction (BFR) training is a training strategy involving the use of cuffs or wraps placed around a limb during exercise to maintain arterial inflow to the muscle while preventing venous outflow. Blood flow restriction training with resistance has been shown to improve muscular power, sprinting speed, strength, hypertrophy and endurance. Non-resistance training methods using BFR, such as walking, may increase strength and hypertrophy however the effects on aerobic capacity are less uncertain and the research in this area is limited. Purpose: to evaluate the effects of three weeks of BFR walk training on VO 2 max, 1. 5 mile run times, and muscular size. Methods: Ten well trained males underwent three weeks of lower extremity BFR walk training. Pre-and post -measurements of VO 2 max, 1. 5 mile run times, and thigh muscle cross sectional area were recorded. Results: Blood flow restriction walk training resulted in significant improvements in VO 2 max (p=. 034), significant decreases in 1. 5 mile run time (p=. 024) and significant increases in thigh muscle cross sectional area (p=. 016). Conclusion: BFR walk training represents a singular training methodology for improving aerobic capacity, endurance and muscular size at low training volumes and intensities. This may be beneficial for individuals undertaking concurrent strength and endurance training. Introduction A novel training strategy to circumvent the injury risk and time constraints of conventional training is blood flow restriction training. Blood flow restriction training is a method of inducing training adaptations in skeletal muscle by applying pneumatic cuffs or bands over the proximal portions of the either the upper or lower limbs (Loenneke et al. , 2012). Previous research has demonstrated that blood flow restriction training (BFR) has positive effects on skeletal muscle hypertrophy, strength and power (Scott et al. , 2015). Several studies have provided compelling data that exercise in conjunction with BFR maintains aerobic capacity and leads to muscle hypertrophy and strength increases (Sakamaki , Bemben & Abe, 2011). Blood flow restriction training may be a novel means of overcoming the contradiction between aerobic training and high intensity resistance training. Methods and Procedures, cont’ Table 1. Descriptive characteristics of participants (Mean ± SD) It is hypothesized that blood flow restriction walk training will significantly improve VO 2 max and 1. 5 mile run times. Methods and Procedures • This study was approved by the Texas A&M University-San Antonio Institutional Review Board. • Ten participants (table 1) read and signed an informed consent form. • Data was collected at The Human Performance Laboratory Texas A&M University-San Antonio and Lackland AFB San Antonio, TX. • Selection criteria for this study included those airmen who were healthy, had no musculoskeletal injuries, and were not on any medications that could impact blood flow. • All subjects underwent a basic medical screening which included height, weight, blood pressure (BP), resting heart rate (HR), ventilatory respirations, and completion of the PAR-Q. • Total thigh muscle cross-sectional area was measured and estimated with a flexible fiberglass tape to measure thigh circumference (Ct) 20 cm above the knee, fat-plus-skin thickness (SQ) was measured over the quadriceps, 20 cm above the knee using calipers and the distance across the medial and lateral femoral condyles (de) was measured with calipers. Thigh muscle cross sectional (CSA) area was then calculated using the following equation: CSA = 0. 649 x ((Ct/π – SQ)2 – (0. 3 x de)2). Age (yrs) 34. 3± 7. 07 Height (cm) 178. 3± 1. 06 Weight (kg) 85. 0± 1. 98 • All subjects then underwent VO 2 max testing at the TAMU-SA laboratory using a standard Bruce protocol, which started at a 10% grade at 2. 7 kilometers per hour (kph) (1. 7 mph) for stage one, then increase in both speed and grade every three minutes. • At least 24 hours after the VO 2 max test, subjects then ran a 1. 5 mile run for time at an outdoor 400 m track. Subjects were fitted with a FS 2 Polar HR monitor and then given 10 minutes to perform a self-selected warm-up. When more than one subject was being tested at the same time, starts were staggered in order to avoid pacing with other subjects. Time was kept with a standard stop watch and recorded for each lap, as well as HR. At the end of six laps, RPE was recorded as well as average and maximal HR. • The intervention was three weeks in length during which all subjects participated in a total of 15 sessions, five sessions per week. The group used a KAATSU Global Nano pneumatic blood flow restriction device (Tokyo, Japan) with inflatable cuffs around the proximal portion of the thigh. • At the start of each training session optimal pressure for cuff inflation was determined per the instructions provided by KAATSU Global. • The exercise protocol required the test subjects to walk on the treadmill at a speed equivalent to 45% VO 2 reserve (%VO 2 R). • The subjects proceeded to walk at a speed equivalent to their 45% VO 2 R for a 20 minute training session. Each 20 minute session was broken down into five stages: 4 minutes at a 1% grade, 4 minutes at a 2% grade, 4 minutes at a 3% grade, 4 minutes at a 4% grade and 4 minutes at a 5% grade. • At the conclusion of the three week protocol, all subjects had their VO 2 max, thigh muscle cross sectional area and 1. 5 mile run times reevaluated in the same manner as described above and the variables were analyzed for any significant differences. • Hypothesis Total (N=10) Statistics: Repeated measures ANOVA were used to assess the differences between groups for VO 2 max, 1. 5 mile run and thigh muscle cross-sectional area. Alpha was set at. 05 for all tests. All statistics were run using SPSS v 23 (Chicago, IL). Results • A repeated measures ANOVA revealed that significant differences (F(7) = 6. 92, p =. 034) existed between pre-BFR VO 2 max (44. 2 ml/kg/min ± 7. 3 ml/kg/min) and post-BFR VO 2 max (45. 7 ml/kg/min ± 6. 4 ml/kg/min), which was a 3. 5% improvement. • Similarly, significant differences (F(7) = 8. 17, p = . 024) existed between pre-BFR 1. 5 mile run times (643 sec. ± 75 sec. ) and post-BFR 1. 5 mile run times (636 sec. ± 73 sec. ), which represented a 7 second improvement. • Finally, significant differences (F(7) = 9. 95, p =. 016) existed between pre-BFR thigh muscle cross sectional area (67. 4 cm 2 ± 38. 3 cm 2) and post-BFR thigh muscle cross sectional area (95. 0 cm 2 ± 32. 0 cm 2), which was a 41% increase. Results • The results of this study demonstrated a 3. 5% improvement in VO 2 max in well-trained males aged 24 to 47. • The results of the current study revealed a statically significant decrease in 1. 5 mile run times which, on average, there was seven second decrease. • The results of this study revealed a 41% statically significant increase in thigh muscle cross sectional area. Conclusion The hypothesis is retained as results suggest low intensity BFR walk training does significantly improve aerobic capacity, running endurance performance and skeletal muscle hypertrophy. Other studies also show significant imporovements in aerobic capacity (Abe et al. , 2010; Corvino et al. , 2014) and increases is muscle mass (Abe et al. , 2006), however, there is no other study that could be found that has evaluated the effects of nonresistance BFR training on endurance running performance. Therefore, based on the evidence one can conclude that BFR walk training is an acceptable singular methodology that results in simultaneous improvements in aerobic capacity, endurance performance and skeletal muscle hypertrophy at low intensities and low volumes. Limitations of this study include the low sample size and future studies should utilize training protocols of varying intensites and occlusion to further identify minimal levels for improvements. References Abe, T. , Fujita, S. , Nakajima, T. , Sakamaki, M. , Ozaki, H. , Ogasawara, R. , Sugaya, M. , Kudo, M. , Kurano, M. , Yasuda, T. , Sato, Y. , Ohshima, H. , Mukai, C. & Ishii, N. (2010 b). Effects of low -Intensity cycle training with restricted leg blood flow on thigh muscle volume and VO 2 MAX in young men. Journal of Sports Science and Medicine, 9(3), 452 -8. Abe, T. , Kearns, C. F. & Sato, Y. (2006 b). Muscle size and strength are increased following walk training with restricted venous blood flow from the leg muscle, Kaatsu-walk training. Journal of Applied Physiology, 100(5), 1460 -6. Cook, C. J. , Kilduff, L. P. & Beaven, C. M. (2014). Improving strength and power in trained athletes with 3 weeks of occlusion training. International Journal of Sports Physiology and Performance, 9(1), 166 -72. Corvino, Rogério Bulhões, Fernandes Mendes de Oliveira, Mariana, Penteado dos Santos, Rafael, Denadai, Benedito Sérgio, Caputo, Fabrizio. (2014). Brazilian Journal of Kineanthropometry & Human Performance, 16(5), 570 – 578. Park, S. , Kim, J. K. , Choi, H. M. , Kim, H. G. , Beekley, M. D. , Nho, H. (2010). Increase in maximal oxygen uptake following 2 -week walk training with blood flow occlusion in athletes. European Journal of Applied Physiology, 109, 591 – 600. Kubota, A. , Sakuraba, K. , Sawaki, K. , Sumide, T. & Tumara, Y. (2008). Prevention of disuse muscular weakness by restriction of blood flow. Medicine and Science in Sports and Exercise, 40(3), 529 -34. Knapik, J. J. , Staab, J. S. , & Harman, E. A. (1996). Validity of an anthropometric estimate of thigh muscle cross-sectional